1. Field
Embodiments relate to optical logic gates and a method for generating logic signals using a DNA based nanostructure.
2. Description of the Related Art
A logic circuit (for example, NOT, AND, OR, or the like) refers to a circuit having a function of logically processing numerical information and generating an output. Until now, the logic circuit has been generally implemented based a semiconductor. However, the conventional semiconductor based information processing technique has recently reached the physical limit in its processing rate and degree of integration.
In order to overcome the limit of an available speed of the semiconductor based information processing technique, the information processing technique using light is considered as an alternative. A conventional light based logic circuit uses a non-linear optical characteristic of an optical element. However, in order to implement a non-linear characteristic of general optical elements, light with great intensity is required, which becomes an obstacle in applying the non-linear optical technique to a logic circuit.
Another alternative of the logic circuit configuration using optical signals is a technique of giving a logic value to a polarization state of light and processing signals through polarization plane control. This method based on the polarization state controlling technique may give a logic circuit using a low-power signal while maintaining the advantage of a rapid processing rate of the optical signal. Generally, a polarization plane of an optical signal is controlled using a wave plate. A phase difference is generated between polarization states due to birefringence of the wave plate, and accordingly, the polarization plane of the transmitting light is rotated. However, this wave plate has problems of difficult characteristic control according to wavelengths, difficult in miniaturization and integration, and high production costs.